Conventional transceivers include a pair of OSAs, i.e. a transmitter optical sub-assembly (TOSA) (not shown) and a the receiver optical sub-assembly (ROSA) 1, illustrated in FIG. 1. The OSAs are electrically connected to a printed circuit board (PCB) 2 via metal leads 3 or by metal leads 3 and a flexible circuit (flex) cable 4. The OSAs 1 and the PCB 2 are mounted in a transceiver module housing, generally indicated at 6, which comprises a lower case 7 and an upper case 8. Heat sinking fins 9, or other suitable heat sinking elements, e.g. pins, extend from the upper case 8 for removing heat from the module housing 6.
Increasing data rates, e.g. in excess of 10 Gb, required by the latest optical transceivers, causes in an increase in power dissipation by the active components therein resulting in an increase in undesirable heat, which must be removed. Hindering the removal of the heat is the industry's desire to use low-cost packaging, such as transistor outline (TO) cans, which are constructed out of materials having poorer thermal conductivity than the more expensive ceramic packaging alternative. Moreover, an industry shift to flex cable for connecting the OSA 1 to the PCB 2 has eliminated the heat sinking provided by the transfer of heat via the leads 3 to the PCB 2.
An object of the present invention is to overcome the shortcomings of the prior art by providing a direct thermally conductive path between an OSA and the module housing without interfering with the RF performance of the OSA and without taking up much valuable space.